1. Technical Field
The present invention relates to a ball joint for connection between two relatively movable parts, and more particularly, to a ball joint for connection between a steerable vehicle wheel and a rack of a rack and pinion steering gear.
2. Description of the Prior Art
A conventional ball joint includes a ball stud in a socket. A bearing is interposed between a ball portion of the ball stud and the socket. The ball stud and socket move relative to each other. A ball joint may be used in a number of different ways. In some uses of a ball joint, undesirable vibration may be transferred through the ball joint.
A ball joint is typically associated with a steering mechanism and transmits force between the steering mechanism and a steered wheel of a vehicle. Thus, the ball joint transfers vibration from the steered wheel to the steering gear. Accordingly, road shocks are transmitted from a steerable wheel of the vehicle through the ball joint to the steering gear. This vibration may be transmitted to a steering wheel of the vehicle and be objectionable to a vehicle operator.
In accordance with one feature of the present invention, an apparatus includes a housing, a ball stud, a first bearing layer, and a second vibration dampening layer. The housing defines a chamber and has an opening in communication with the chamber. The ball stud has a ball portion located in the chamber and a stud portion extending from the ball portion through the opening. The ball portion has a center. The stud portion has a longitudinal axis intersecting the center. The first bearing layer is disposed in the chamber and engages the ball stud. The ball stud is rotatable about the center relative to the first bearing layer. The second vibration dampening layer dampens vibration transmitted between the housing and the ball stud.
In accordance with another feature of the present invention, an apparatus includes a housing, a ball stud, a first bearing layer, and a second vibration dampening layer. The housing defines a chamber. The housing has an opening in communication with the chamber. The ball stud has a spherical ball portion located in the chamber and an elongate stud portion extending from the ball portion through the opening. The ball portion has a center and a partially spherical outer surface. The stud portion has a longitudinal axis intersecting the center. The first bearing layer has an inner spherical surface and an outer spherical surface. The first bearing layer is disposed in the chamber. The inner spherical surface of the first bearing layer engages the outer spherical surface of the ball portion. The ball portion is slidable relative to the first bearing layer. The second vibration dampening layer dampens vibration transmitted between the housing and the ball stud. The second vibration dampening layer has an inner spherical surface. The inner spherical surface of the second vibration dampening layer engages the outer spherical surface of the first bearing layer.